1. Field of the Invention
The present invention relates to a focus adjustment device for carrying out focus adjustment using a phase difference AF method, based on output of an image sensor that has imaging pixels and focus detection pixels, and to an imaging device and a focus adjustment method.
2. Description of the Related Art
A focus adjustment device, that forms a subject image that has been formed using an photographing optical system having focus detection pixels arranged at positions of some imaging pixels that are arranged two dimensionally, and also carries out focus adjustment for the photographing optical system using a pupil-division phase difference method, is known. With an image sensor of this focus adjustment device, incident angles to photoelectric conversion elements of focus detection pixels, of pairs of light flux for focus detection that have passed through regions of differing exit pupils of the photographing optical system, vary with increasing distance from points of a light receiving surface of the image sensor that intersect the optical axis of the photographing optical system, and focus detection precision is lowered.
A focus adjustment device has therefore been proposed that sets a positional relationship between positions of microlenses for pupil-division and positions of focus detection pixels in accordance with image height of a light receiving surface of an image sensor (Japanese patent laid-open No. 2009-290157 (refer to patent literature 1)).